<!DOCTYPE html>
<html lang="en">
<head>
  <meta charset="UTF-8">
  <title>Title</title>
</head>
<body>
<div id="app" v-if="con">
  {{ message }}
</div>
<script src="../js/vue.js"></script>
<script>
    const app = new Vue({
      el: '#app',
      data: {
        message: "你好",
        con: true
      }
    })
</script>
</body>
</html>
